Re: [syzbot] [overlayfs?] WARNING in ovl_listxattr

[Edward Adam Davis]

#syz test

diff --git a/fs/xattr.c b/fs/xattr.c
index 8ec5b0204bfd..3751c9306274 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -491,6 +491,7 @@ vfs_listxattr(struct dentry *dentry, char *list, size_t size)
 
 	if (inode->i_op->listxattr) {
 		error = inode->i_op->listxattr(dentry, list, size);
+		printk("buf: %s, size: %lu, res: %ld, sb: %s, %s\n", list, size, error, inode->i_sb->s_type->name, __func__);
 	} else {
 		error = security_inode_listsecurity(inode, list, size);
 		if (size && error > size)
@@ -1466,12 +1467,14 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
 	int err = 0;
 
 	err = posix_acl_listxattr(inode, &buffer, &remaining_size);
+	printk("inode: %p, buf: %s, size: %lu, res: %d, remaining_size: %ld, %s\n", inode, buffer, size, err, remaining_size, __func__);
 	if (err)
-		return err;
+		goto out;
 
 	err = security_inode_listsecurity(inode, buffer, remaining_size);
+	printk("2inode: %p, buf: %s, size: %lu, res: %d, remaining_size: %ld, %s\n", inode, buffer, size, err, remaining_size, __func__);
 	if (err < 0)
-		return err;
+		goto out;
 
 	if (buffer) {
 		if (remaining_size < err)
@@ -1479,6 +1482,7 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
 		buffer += err;
 	}
 	remaining_size -= err;
+	err = 0;
 
 	read_lock(&xattrs->lock);
 	for (rbp = rb_first(&xattrs->rb_root); rbp; rbp = rb_next(rbp)) {
@@ -1498,6 +1502,8 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
 	}
 	read_unlock(&xattrs->lock);
 
+	printk("3inode: %p, buf: %s, size: %lu, res: %d, remaining_size: %ld, %s\n", inode, buffer, size, err, remaining_size, __func__);
+out:
 	return err ? err : size - remaining_size;
 }